Liquid heater



A. W. PETERS LIQUID HEATER Nov. 11, 1952 2 SHEETS-SHEET 1 Filed Feb. 5, 1949 CNN INVENTOR. AW. Pe fe/"s W n r 0 f f A A. W. PETERS Nov. 11, 1952 LIQUID HEATER 2 SHEETS-SHEET 2 Filed Feb. 5, 1949 IN VEN TOR.

Affor'ney Patented Nov. 11, 1952 LIQUID HEATER Arthur W. Peters, Toledo, Ohio, assignor to Surface Combustion Corporation, Toledo, Ohio, a

corporation of Ohio Application February 5, 1949, Serial No. 74,839

4 Claims.

The present invention relates to a fuel burning heater for heating a stream of liquid and has for its general object to provide an improved heater for that purpose. For a consideration of what I consider to be novel and my invention attention is directed to the following specification and the claims appended thereto.

In the accompanying drawings forming part of this specification Fig. 1 is an axial sectional view of the improved heater with the burner therefor in elevation.

Fig. 2 is a transverse section on line 22 of Fig. 1.

Fig. 3 is a diagrammatic layout of features embodied in the improved heater.

In the present invention, the heater comprises an annular chamber 5 wherein the liquid is heated as it flows therethrough, the chamber being defined by radially spaced inner and outer cylindrical shells 6 and 7, respectively, and front and rear annular end plates or walls 8 and 9, respectively. The inner cylindrical shell 6 defines a cylindrical combustion chamber 10 which is internally heated by a whirling mass of flaming gases from any preferred type of a flame-whirling 1 burner H at the front end of the combustion chamber, the burner being shown as comprising a front wall 29 which is radially extended as indicated at [2 for detachable securement to a transverse wall I9 forming part of the heater structure.

The flame-whirling burner comprises a tangential air supply inlet 42 for causing combustion air to whirl inside the outer wall of the burner H and to whirl as it spills out over the front wall 29 into the combustion chamber It, and a tubular duct 4| for delivering an atomized mixture of fuel and air to the combustion chamber within the whirling combustion supporting air stream, thus producing in the chamber a whirling mass of flaming gases. The particular flamewhirling burner preferred is described in more detail in my copending application Serial No. 78,025, filed February 17, 1949.

The chamber 5 is longitudinally divided from end to end by a longitudinally and radially extending partition wall [3 which forms a barrier to the flow of liquid across the plane thereof. Two openings l4 and in the outer cylindrical shell I at opposite sides of the dividing or barrier wall 13 constitute an inlet and outlet, respectively, for the liouid to be heated so that the liouid must flow around the inner cylindrical shell 6 in flo ing from said inlet to said outlet.

In order to flow in said direction the liquid is caused to flow back and forth between the end walls 8 and 9 of said annular chamber or container 5 in a channel defined by an annular series of laterally spaced baflles or partition Walls [6 and I! which extend alternately from the opposite end walls 3 and 9 of said container and terminate short of the end wall which is opposite the end wall from which said bafiles extend so that the stream of liquid makes a reverse bend at the short end of each baille in flowing from one to the other of the consecutively adjacent parallel channels defined by said bafiles. The general arrangement will be readily understood by reference to Fig. 3 wherein the bafiies or partition walls l6 extend from the front end wall 8 of said container to a point short of the rear end Wall 9 thereof and the walls I! extendfrom the rear end wall 9 to a point short of the front end wall 8, the direction of flow being indicated by the arrows. This flow path between the adjacent partition walls I6 and I! may be divided into parallel flow paths by radial dividing walls I8 therebetween, these walls I8 terminating short of the end walls 8 and 9. All of the walls [6, l1 and 18 are welded to the outer side of the inner cylindrical shell 6 and therefore constitute in effect heat conducting fins extending radially outward from the internally heated cylindrical shell 6. The outer cylindrical shell I is formed by wrapping a sheet metal wall around the inner cylindrical shell 6 and welding the abutting edges of said wall to the outer edge of the longitudinal barrier wall [3 as indicated at 20. Because of. the relatively long linear path provided by the alternating partition walls [6 and I1 and of the heat transferred to the liquid by said Walls, the liquid may be passed through the liquid-holding container or chamber 5 with relatively high velocity and yet be adequately heated.

The heater also comprises an annular series of longitudinally extending flue tubes 2| which extend between and through the end walls 8 and 9 of the annular container 5, the tubes extending along the channels provided by the radially extending heat conducting fins or partition walls 16 and I! hence the liquid flowing in these channels will also be heated by contact with said flue tubes. Wall structure comprising an end wall 22 defines a connecting passage between one end of the circular row of flue tubes and the discharge end of the combustion chamber H] for directing products of combustion from the latter to the intake end of the flue tubes.

The flue gas issuing from the flue tubes 2| flows into an annular exhaust manifold 23 around the front portion of the outer cylindrical shell 1 of 3 the heater, the outer side wall of the manifold being indicated at 220 and the outlet at 24. An extension ZZI of the inner cylindrical shell 6 of the heater serves to isolate the interior of said manifold from the adjacent interior end of the combustion chamber I0.

As previously stated, the burning gases from the burner ll initially advance with a whirling motion. However, at a point about midway between the ends of the combustion chamber I0, there is positioned a transversely extending baiile plate 26 having a relatively restricted central opening 21 wherethrough the advancing gases flow with such resultant turbulence as Will promote rapid combustion of any unburned fuel in said gases. Also by arranging a cylindrical plug 28 within the rear portion of the combustion chamber to restrict the outlet therefrom to a relatively narrow annular passage 30 there is a rapid transfer of heat from the outgoin flue gases to the adjacent wall of the inner cylindrical shell 6 due to the relatively high velocity of the flue gas in said passage 30. The plug 28 conveniently takes the form of a drum which .prolects from the end wall 22.

A heater constructed in accordance with the present invention makes it possible to maintain the walls of the inner cylindrical shell 6 at a temperature not exceeding 50 degs. F. above the temperature of the liquid being heated even though the temperature of the combustion gases may be as high as 2500 degs. F. Heat insulating material 25 about the external parts of the heater reduces heat loss therefrom to minimum.

' The present heater has special utility in connection. with the heating of heat transfer liquids which are subject to thermal decomposition at elevated temperatures since it permits the safe heating of these liquids to a temperature which is relatively close to their decomposition temperature thereby permitting these liquids to be utilized at maximum operating temperatures.

Although certain aspects of the heater have been described with considerable particularity it will be understood that no limitations are intended except as expressed in the following claims.

I claim:

1. In apparatus for heating a stream of liquid, in combination, a cylindrical metal shell forming within said shell a cylindrical combustioni chamber, means comprising a burner at one end of said shell for circulating hot gases through said chamber, means comprising a Wall which surrounds said cylindrical shell in spaced relation and axially spaced annular end plates between said wall and said cylindrical shell for defining with the exterior side of the cylindrical shell 2. closed annular chamber for the liquid to be heated, a'circular series of flue tubes extending within said annular chamber and through said annular end plates, means for directin towards the intake ends of said flue tubes for flow therethrough the hot gases issuing from the exhaust end of said combustion chamber, means forming an inlet to and an outlet from said annular chamber for a stream of said liquid, a first partition wall extending the full length of said annular chamber, said inlet and outlet being relatively close to each other and lyin adjacent to said partition wall at opposite sides thereof so that said stream of liquid must flow around said cylindrical shell to flow from said inlet to said outlet, a circular series of secondary partition walls alternately extending from. the opposite annular end plates of said annular chamber and being shorter than the distance between said end plates to provide within said annular chamber for said stream of liquid a continuous flow path which extends back and forth between the ends of said annular chamber from said inlet to said outlet, and a cylindrical plug within said combustion chamber at the exhaust end thereof to restrict the effective gas discharge area thereof to a relatively narrow annular passage next to the inner face of said cylindrical shell.

2. In apparatus for heating a stream of liquid, in combination, a cylindrical metal shell forming within the shell a cylindrical combustion chamber, means comprising a flame-whirling burner for supplying a whirling mass of flaming gases for internally heating the shell and circulating hot gases therethrough to the exhaust end thereof, means comprising a wall which surrounds said cylindrical shell in spaced relation and axially spaced annular endplates between said wall and said cylindrical shell for defining with the exterior side of the cylindrical shell a closed annular chamber for the liquid to be heated, means forming an inlet to and an outlet from said annular chamber for a stream of said liquid, and a cylindrical plug comprising an annular metallic sidewall and an endwall Within said sidewall axially remote from the burner end of the combustion chamber, said sidewalls extending from next adjacent the exhaust end of the combustion chamber a substantial distance into said chamber toward the burner end thereof to allow said sidewall to be heated by combustion Within said chamber and radiate heat to the adjacent metal shell, and to restrict the effective discharge of the combustion chamber to a relatively narrow passage, next to the inner face of the cylindrical shell and for a substantial distance therealong, Wherethrough said exhaust gases shall pass from the chamber.

3. In apparatus according to claim 2, the 0mm bination which comprises an annular plate extending into the combustion chamber from said cylindrical metal shell at a point intermediate the ends of the chamber and wherein the sidewalls of the cylindrical plug extend from the exhaust end of the chamber to a point therein short of said annular plate whereby accelerated combustion of gases upon passing through said annular plate will take place substantailly within said plug.

4. In apparatus for heating a stream of liquid, in combination, a cylindrical metal shell forming Within the shell a cylindrical combustion chamber, heating means comprising a flamewhirling burner for supplying hot gases to one end of said chamber for circulation therethrough next adjacent said shell, means comprisin a wall which surrounds said cylindrical shell in spaced relation and axially spaced annular end plates between said wall and said cylindrical shell for defining with the exterior side of the cylindrical shell a closed annular chamber for the liquid to be heated, a circular series of flue tubes extending within said annular chamber and through said annular end plates, means for directing toward the intake ends of said flue tubes for flow therethrough the hot gases issuing from the exhaust end of said combustion chamber, means forming an inlet to and an outlet from said annular chamber for a stream of said liquid, a first partition Wall extending the full length of said annular chamber, said inlet and outlet being relatively close to each other and lying adjacent to said partition Wall at opposite sides thereof so that said stream of liquid must flow around said cylindrical shell to flow from said inlet to said outlet, and a circular series of secondary partition walls separating the flue tubes from each other and alternately extending from the opposite annular end plates and being shorter than the distance between said end plates to provide within said annular chamber for said stream of liquid a continuous flow path which extends back and forth between the ends of said annular chamber and parallel and adjacent to substantially the entire length of said flue tubes from said inlet to said outlet.

ARTHUR W. PETERS.

REFERENCES CITED The following references are of record in the file of this patent:

Number Re. 9,272 101,718 5 186,774 373,835 664,186 984,754 1,903,313

Number 6 UNITED STATES PATENTS Name Date Bigelow June 29, 1880 Dunning Apr. 12, 1870 Wainwright Jan. 30, 1877 Lindemuth Nov. 29, 1887 Strobel Dec. 18, 1900 Eijdman Feb. 21, 1911 Johnson Apr. 4, 1933 Anderson et al Jan. 3, 1939 Curtis Feb. '7, 1939 Toner Nov. 25, 1941 Way et a1 Aug. 28, 1945 I-Io-lthouse Nov. 2, 1948 FOREIGN PATENTS Country Date Great Britain Aug. 20, 1913 

